The present invention relates to a minute, highly efficient diffraction grating, and a process for producing the same.
A diffraction grating is generally produced by engraving a large number of parallel lines on a metallic film deposited on a glass plane. This conventional process hardly provides a minute diffraction grating, and hence cannot be adapted to production of a diffraction grating to be incorporated into a miniature optical circuit such as an optical integrated circuit. It is also inadequate for producing a high resolution diffraction grating to be used for electromagnetic waves with a short wavelength, such as soft X-rays. Although there have been instances of using multilayered films of semiconductor as a reflection film (e.g. Sakai et al., Abstract for the 45th Meeting of the Japan Society of Applied Physics (Fall Meeting, 1984) p. 152, 12a - N - 4), there have heretofore been no instances of producing a minute diffraction grating from multilayered films of compound semiconductors.